As disclosed in U.S. Pat. No. 3,706,919, it is known that dimension-measuring probes may be designed using the known variation of capacitance between conductors with separation to provide a highly accurate and automatic non-contact dimensional or distance gauge which is particularly useful in present day industrial applications. Dimension gauge equipment setup and calibration for surface investigation is a time consuming part of capacitive gauging, but necessary if accuracy is to be maintained. Among the problems of the prior art are gradual changes in probe calibration produced by environmental or circuit effects. These variations cause intolerably large changes in electrical output signals of circuitry operating with the probe despite no variation in the capacitance being sensed. Furthermore, because the relationship between output voltage of the probe and measured distance is nonlinear and linearizing circuitry is often employed, changes in the output of the probe from these effects causes the linearity to also be shifted.